Evan ii



(No Model.)

B. H..BOWBN. GOMMUTATOR BRUSH.

r 1 Wm m m n IHWU w v by i Patented Mayl3. 1890.

UNITED STATES PATENT OFFICE.

EVAN ll. BOIVEN, OF AKRON, OI'IIO, ASSIGNOR OF TIVO-THIRDS TO LEIVIS A. SMITH AND JOHN HENRY KRUSE, OF SAME PLACE.

COMMUTATOR-BRUSH.

SPECIFICATION forming part of Letters Patent No. 428,038, dated May 13, 1890.

Application filed August 8, 1889. Serial No. 320,077. (No model.)

To all whom it may concern.-

Be it known that I, EVAN ll. BOWEN, acitizen of the United States, residing at Akron, in the county of Summit and State of Ohio,

' have invented a certain new and useful Cominutator-Brush, of which the following is a specification.

Myinvention has relation to improvements in brushes for commutators for dynamo-elec- IO trio machines and electric motors.

The object of my invention is to produce a new and improved brush which shall efticientl y convey the electric current, and which will, without the use of anylubricant, reduce [5 the wear of the brush and commutator to a minimum.

My invention consists in adopting as a brush a carbon stick similar in composition to that prepared and constructed for electricare lamps,and having sufficient rigidity to be self-supporting, and in peculiarly-shaped clamps for retaining said sticks tangential to the periphery of the connnutator.

The manner of applying my invention is illustrated in the accompanying drawings, in which similar letters of reference indicate like parts, and in which Figure 1 is a plan of a commutator and brush clamps having cylindrical carbon brushes; Fig. E3,an end elevation of the same,

and Fig. 3 a section of the clamp with carbons therein.

In the drawings, A is the commutator, which may be of any desired pattern or form, oppo- 3 5 site which are the brush-clamps B I which are connected with the d ynamo-frame in any of the known methods. Each clamp consists of a head, preferably cylindrical, mounted on a short shaft I), by which they are supported,

and which is connected with the dynamo through the slot and ring at the end of the finger and rests in the groove in the jaw F, where it is securely fastened by a plate H and set-screw. The end of stick thus rests on the commutator tangential to its periphery, and is ordinarily of sufficient rigidity to be self supporting; but to afford additional strength and prevent its breaking from a sudden blow I provide the linger G,l1ereinbefore described, and hence when the stick is sufficiently rigid these lingers maybe omitted.

I have illustrated in the drawings carbon sticks cylindrical in form similar to those used in are lamps; but this form is not essential, as any form of cross-section desired may be adopted, the essential idea of my lllVGlP tion being the adoption of a prepared carbon stick to take the current from the commutator, in combination with a clamp peculiarly constructed. for holding its end against and tangential to the periphery of the commuta- 7o tor.

These brushes not only convey the current freely, affording little resistance thereto, but are neither rapidly worn themselves, nor do they wear the commutator as rapidly as metallic brushes.

I claim 1. The combination, with a commutator of a dynamo-electric machine, of a rigid carbon stick and a clamp having a grooved jaw, a compressing-plate, and a set-screw to receive said stick and retain it against and tangential to the periphery of the commutator, substantiail y as shown.

2. The combination, with a commutator of a dynamo-electric machine, of a rigid carbon stick and a clamp having a jaw provided with a projecting finger terminating in a ring, a compressing-plate, and a set-screw for retaining the stick against the commutator tangeno tial to its periphery, substantially as shown.

In testimony that I claim the above I hereunto set my hand.

EVAN I-I. BOIVEN.

In presence of B. W. I-IALLo'WAY, O. P. HUMPHREY. 

